Swift: Allow configuring container storage policies

This adds the `swift_storage_policy` configuration option for setting
the storage policy Gnocchi will use when creating new Swift containers.

When unset the storage policy will not be configured when creating
containers, in which case Swift will use the default storage policy.

gnocchi/incoming/swift.py

@@ -36,6 +36,11 @@ class SwiftStorage(incoming.IncomingDriver):
     def __init__(self, conf, greedy=True):
         super(SwiftStorage, self).__init__(conf)
         self.swift = swift.get_connection(conf)
+        self._put_container_headers = {}
+        if conf.swift_storage_policy:
+            self._put_container_headers["X-Storage-Policy"] = (
+                conf.swift_storage_policy
+            )
 
     def __str__(self):
         return self.__class__.__name__
@@ -45,11 +50,13 @@ def _get_storage_sacks(self):
         return json.loads(data)[self.CFG_SACKS]
 
     def set_storage_settings(self, num_sacks):
-        self.swift.put_container(self.CFG_PREFIX)
+        self.swift.put_container(self.CFG_PREFIX,
+                                 headers=self._put_container_headers)
         self.swift.put_object(self.CFG_PREFIX, self.CFG_PREFIX,
                               json.dumps({self.CFG_SACKS: num_sacks}))
         for sack in self.iter_sacks():
-            self.swift.put_container(str(sack))
+            self.swift.put_container(str(sack),
+                                     headers=self._put_container_headers)
 
     def remove_sacks(self):
         for sack in self.iter_sacks():

gnocchi/storage/swift.py

@@ -67,6 +67,10 @@
     cfg.StrOpt('swift_container_prefix',
                default='gnocchi',
                help='Prefix to namespace metric containers.'),
+    cfg.StrOpt('swift_storage_policy',
+               default=None,
+               help='Storage policy to use when creating containers. '
+                    'When unset, the default Swift storage policy is used.'),
     cfg.StrOpt('swift_endpoint_type',
                default='publicURL',
                help='Endpoint type to connect to Swift',),
@@ -93,6 +97,11 @@ def __init__(self, conf):
         super(SwiftStorage, self).__init__(conf)
         self.swift = swift.get_connection(conf)
         self._container_prefix = conf.swift_container_prefix
+        self._put_container_headers = {}
+        if conf.swift_storage_policy:
+            self._put_container_headers["X-Storage-Policy"] = (
+                conf.swift_storage_policy
+            )
 
     def __str__(self):
         return "%s: %s" % (self.__class__.__name__, self._container_prefix)
@@ -112,6 +121,7 @@ def _create_metric(self, metric):
         # TODO(jd) A container per user in their account?
         resp = {}
         self.swift.put_container(self._container_name(metric),
+                                 headers=self._put_container_headers,
                                  response_dict=resp)
         # put_container() should return 201 Created; if it returns 204, that
         # means the metric was already created!

gnocchi/tests/base.py

@@ -65,26 +65,32 @@ def skip_if_not_implemented(*args, **kwargs):
 class FakeSwiftClient(object):
     def __init__(self, *args, **kwargs):
         self.kvs = {}
+        self.headers = {}
 
-    def put_container(self, container, response_dict=None):
+    def put_container(self, container, headers=None, response_dict=None):
         if response_dict is not None:
             if container in self.kvs:
                 response_dict['status'] = 204
             else:
                 response_dict['status'] = 201
         self.kvs[container] = {}
+        self.headers[container] = (
+            {header.lower(): value for header, value in headers.items()}
+            if headers
+            else {}
+        )
 
     def get_container(self, container, delimiter=None,
                       path=None, full_listing=False, limit=None):
         try:
-            container = self.kvs[container]
+            container_objs = self.kvs[container]
         except KeyError:
             raise swexc.ClientException("No such container",
                                         http_status=404)
 
         files = []
         directories = set()
-        for k, v in container.copy().items():
+        for k, v in container_objs.items():
             if path and not k.startswith(path):
                 continue
 
@@ -109,7 +115,8 @@ def get_container(self, container, delimiter=None,
             # otherwise.
             end = 1
 
-        return ({'x-container-object-count': len(container.keys())},
+        return ({**self.headers[container],
+                 'x-container-object-count': len(container_objs.keys())},
                 (files + list(directories))[:end])
 
     def put_object(self, container, key, obj):

releasenotes/notes/swift-storage-policy-fa2d73d8714e3a03.yaml

@@ -0,0 +1,8 @@
+---
+features:
+  - |
+    The Swift storage driver can now be configured to create containers
+    with a custom storage policy using the ``swift_storage_policy``
+    option. This allows for overriding the storage policy when using
+    the default policy is not desirable, e.g. to limit object replication
+    to a single region when multi-region replication is the default.